The HEI Core Center for Hearing Research aims to support and facilitate research, foster collaborations and set new research directions in the following four areas: 1) human subject recruitment, 2) engineering, 3) imaging/morphology, and 4) animal studies. Core A: Centralized Human Research Subject Database will provide a centralized database of human subjects for investigators at HEI. The goals of the Core are to provide support in recruiting human subjects for participation in research studies at HEI and to improve efficiency and productivity of the research endeavors by making it faster and easier to select appropriate subjects. The Core also aims to foster collaborations among investigators who will take advantage of the opportunities provided by this core. Core B: Engineering will develop and maintain hardware and software expertise on real-time digital signal processing (DSP). The Core will also will interact with project-specific engineers to interface their custom input and output needs to the DSP core modules. In addition, the Core will provide basic equipment configuration and calibration services for standard audio equipment used for behavioral hearing as well as ABR and OAE measurement systems. Core C: Imaging and Morphology aims to provide state-of-the-art morphology and microscopy services and training to HEI scientists. Such services include inspection and maintenance of all imaging equipment, image storage, and providing training. The addition of a histology technician will help towards the achievement of this objective. The Core will perform inspection and maintenance of all imaging equipment. The Core will also encourage collaboration and dissemination of information about advances in the field of imaging. Core D: Mutant Animal Models aims to provide excellence in animal husbandry, including health monitoring, breeding and record keeping for mice and other species. Its personnel will also be responsible for DNA isolation and PCR genotyping, as well as for primer design and ordering. The addition of a husbandry and a genotyping technician will allow us to perform these functions efficiently. Another aim of this Core is to increase the opportunity for interactions and collaborations.